>>964990Angles. A smaller tyre will have a steeper "bow" that slams into irregularities rather than rolling over them.
Also, an air spring is not linear but progressive. The less air volume you have, the more that starts to show. Even if (loaded weight) air pressure and contact patch is the same, a larger volume tyre will feel more plush due to more air giving a more linear air spring rather than "bottoming out"(=non-linear damping), and more tyre carcass having more total give, further smoothing the air suspension.
On the other hand, if you run very large tyres but at very, very low pressures you might need a bit of that progressiveness to keep from denting your rims all the time. Then a stiff, "dead" tyre cord and smaller rim diametre might be the best thing.
Everything always depends. It sucks.